About thumb_width, padding and columns parameters

Since the thumbs are placed in grid and the original thumbs are 80x80 pixels you should take care of them based on your sidebar size.
The padding is the space between thumbs, while the columns tell the plugin to reset the padding on the last thumb per row.
So, with the default parameter, you should have a 280px wide sidebar.

Further questions

If you have any questions or comments, feel free to leave a comment on the project page and I will respond as soon as I can.